Representation of the Bitcoin virtual currency standing on the PC motherboard is seen in this illustration picture, February 3, 2018. REUTERS/Dado Ruvic/Illustration

WASHINGTON (Reuters) - The Federal Communications Commission said on Thursday an investigation had found that a Brooklyn bitcoin mining operation interfered with T-Mobile US Inc’s (TMUS.O) broadband network.

The company had complained about interference to its 700 MHz LTE network in Brooklyn from radio emissions it said were coming from a Brooklyn residence mining for the cryptocurrency - verifying bitcoin transactions.

The FCC said its investigation determined the user was “generating spurious emissions on frequencies assigned to T-Mobile’s broadband network and causing harmful interference.”

The agency’s enforcement bureau said in a letter dated Thursday that continued use of an operation known as “Antminer s5 Bitcoin Miner” would constitute a violation of federal law and could result in fines, criminal prosecution or seizure of the equipment.

T Mobile did not immediately respond to a request for comment.

FCC Commissioner Jessica Rosenworcel said in a tweet the “letter has it all: #bitcoin mining, computing power needed for #blockchain computation and #wireless #broadband interference. It all seems so very 2018.”